1. Field of the Invention
The present invention relates to well perforation assemblies, and more particularly to a cleaning assembly useful in opening well perforations.
2. Description of the Prior Art
In a typical well bore through which fluids are drawn from an underground formation cylindrical well casings are often used which at one or more levels are perforated. As the fluids migrate through the formation to the well bore large quantities of particulate matter are carried along. This particulate matter eventually consolidates around the perforations, finally closing off any flow therethrough.
As a consequence those engaged in the well business have devised in the past a variety of tools which in one way or another reopen the perforation. Some examples of such prior tools are described in U.S. Pat. Nos. 2,464,669 to Brown, 2,233,930 to Witt; 2,213,926 to Brandel; 2,212,784 to McCune; and 3,163,227 to Caldwell. Each of these, while suitable for their purposes, attend to the specific concern at hand.
A perforation cleaning arrangement which localizes the volume exposed to pressure is therefore a desirable mechanism in this setting and it is one such arrangement that is disclosed herein.